Nanotechnology

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Transcript of Nanotechnology

Nanomaterials in Technology Introduction to the Fields of Nanoscience and Nanotechnology -the scientific study of the biological and chemical structures with dimensions ranging from 1- 100 nanometers (MIT, 2011)-‘nano’ comes from the Greek word ‘nanos’ meaning ‘dwarf’-nano refers to 10-9 power, or one billionth -a human hair is about 100,000 nanometers thick -nanotechnology uses materials ranging from 1-100 nanometers to develop materials and instruments on that scale -this technological advancement is responsible for greatly expanding conventional physics by developing new materials on the nanoscale that can potentially give us the ability to control matter on an atomic scale.-nanotechnology has been applied to many different fields of study such as technology, medicine, and the production of energy-many issues surround the field of nanotechnology, such as environmental concerns and the possibilities of the development of weapons that utilize the technology The History of Nanoscience -many scientists began discussing the possible applications of nanoscience throughout the 1800’s and 1900’s, long before the materials could be identified-an American physicist named Richard Feynman gave the earliest speech on nanotechnology, titled “There’s Plenty of Room at the Bottom”, during which he discussed the importance and possibilities “of manipulating and controlling things on a small scale” -in the 1980’s, scientists at IBM invented the atomic force microscope, which allowed scientists to see materials at a scale that was not possible in the past-supercomputers were then able to simulate nanomaterials systems, resulting in large developments in the studies of the structures of nanomaterials and their properties, which resulted in an increase in the research on nanomaterials throughout the 1980’s The History of Nanomaterials in Electronics -arguably the biggest breakthrough that resulted in the development of nanotechnology was the discovery of the buckyball (1985), which was a new shape of carbon molecules, consisting of 60 carbons and a spherical shape-this led to the discovery of the ‘carbon nanotube’ (1991), which are structures that are about 1/6 of the weight of steel, but 100 times stronger-the unique conductivity and heat characteristics of carbon nanotubes led to the development of new technology Why are Nanomaterials used in Electronics? -Electronics utilize the unique characteristics of carbon nanotubes -single-walled carbon nanotubes are extremely thin, hollow, and strong, and they are expected to replace metals in electronic applications in the future-Joules Law states that resistance in a circuit converts electrical energy into heat, but it was recently discovered that carbon nanotubes do not follow this law.-carbon nanotubes produce only 1% of the heat that traditional metals produce -carbon nanotubes have high thermal conductivity because its strong molecular bonds (C-C), which occur in a simple sequence, allows molecular vibrations to move quicker and more efficiently through materials (Darling, 2011)-applying these carbon nanotubes can result in technological advancement on a very large scale The Function and Common Uses of Nanomaterials in Electronics Transistors-conventional microtechnology, which uses materials such as silicon and copper, cannot be improved without using smaller and more efficient materials, such as diamond or carbon nanotubes-carbon nanotube transistors are able to operate at room temperature and only require 1 electron for digital switching (opening and closing switches on an electrical circuit)-carbon nanotubes have also been used to act as a cooling device on transistors, where carbon nanotube layers are used on electric circuits for thermal management Semi-conductors-in a recent study by the University of Maryland, it was determined that carbon nanotubes conduct electricity better than any other material at room temperature-the amount of current that flows through the semi-conductor (how fast electrons move) is about 25% higher than any other semi-conductor-this is because the carbon atoms are more tightly packed together than the atoms used in conventional microtechnology, and this allows a more direct path more electrons to flow, increasing the current Computer Chips-copper wire is conventionally used to connect transistors in computer chips, however, as computer chips become smaller, the size of the wire must also decrease, which lowers the wires’ conductivity, meaning more current is lost and the wire may fail.-using carbon nanotubes instead of copper wire allows the transistors to be packed denser within the computer chip and eliminates the loss of current Other Technological Applications-used in many structural applications, such as in windmill blades, bicycle components, and aircrafts-nanotube ‘ink’ use for printing-using carbon nanotubes to drop oil polluting water Advantages of using Nanomaterials in Technology -as mentioned before, the unique characteristics of nanomaterials allows for smaller and stronger materials to be used in technology-this results in more smaller and more efficient technology that minimizes the loss of current and allows current to travel faster through circuits-it also allows for smaller and lighter materials to be used in structural technology such as aircraft and space craft Disadvantages of using Nanomaterials in Technology-there is no technology that can mass produce carbon nanotubes at this time, meaning the materials need to be grown, which greatly limits the amount that can be produced, making the materials more expensive-they are extremely complex and high tech, meaning slight errors and impurities in the manufacturing process can have detrimental effects on the product-due to long and microscopic nature of the carbon nanotubes, it is possible that health risks could be associated with the accidental inhalation of the materials, similar to asbestos-there is also a fear that these materials can be used in weapons of mass destruction The Future of Nanomaterials in Technology-Paper batteries – carbon nanotubes can be used to allow more current to be stored within batteries-Radio – a ‘nanoradio’ was produced that uses a single carbon nanotube as a receiver-Transistors – as discussed before, the limitation of conventional microtechnology has been reached, and circuits will begin to use more and more carbon nanotubes in the future.